1. Field of the Invention
The present invention generally relates to pour spouts for containers of fluid, and more particularly to a pour spout assembly that permits transfers of fluid (liquid) based on the influence of gravity and limits the tendency for fluid spills or overflow.
2. Description of the Prior Art
As stated in U.S. Pat. Nos. 6,598,630 and 6,871,680, it is desirable to avoid overfilling of fuel to internal combustion engines in lawnmowers, tractors, personal water craft, chain saws and power tools, outboard motors, all terrain vehicle (ATV) type recreational vehicles and even automobiles. Spilled fuel presents health and safety risks to people and the environment in general. As a result, many states have passed environmental legislation which regulates pour spouts which can be used in conjunction with volatile fuels and other liquids.
The opportunity for spills arises from various causes. First, often times the gas tanks in the aforementioned internal combustion engines have very narrow openings which requires precise pouring and/or a facilitating pour spout or funnel to prevent spills. Many times spills occur because the operator of the pour spout does not know when the receiving vessel is full. In these cases, overflows occur before pouring can be terminated.
Yet another cause of spills is the ineffective venting of the container from which the fluid is being transferred. The result of ineffective venting is an uneven fluid flow, and even in some cases surging of the fluid. Surges can cause splashing and an uneven flow makes it extremely difficult to predict fluid levels in the receiving vessel.
Another problem encountered by gravity influenced pour spouts is airlock caused by improper venting. Airlock occurs as a result of improper venting in combination with specific volume and viscosity parameters of the fluid being transferred. Such a condition can result in fluid which will not pour even when the container is inverted. This problem, while annoying, can normally be resolved by turning the container right side up again. However, this only increases the opportunity for spills.
Examples of prior spill-proof pour spouts include U.S. Pat. Nos. 4,598,743, 4,834,151, 5,076,333, 5,249,611, 5,419,378, 5,704,408, and 5,762,117. These pour spouts all have at least the following drawbacks: they do not provide multiple flow rate options and they do not provide childproof locks. Additionally, known pour spouts are limited in their compatibility with multiple vessel types, especially in light of certain state regulations requiring specific spout diameters for certain applications. For example, while some states may require spout outlet diameters on the order of 1 inch, that standard size diameter of a vehicular fuel tank inlet apertures is on the order of ¾ inch.
U.S. Pat. Nos. 6,598,630 and 6,871,680 essentially describe spill-proof pour spout(s) for transferring fluid from a first container to a second container or vessel. The pour spout(s) essentially comprise a base having an inner sleeve extending outwardly therefrom, a conduit member located in the inner sleeve, and an outer sleeve slidingly engaging the inner sleeve. The conduit member has a fluid tube, and air tube and an end cap. The outer sleeve is in a first closed position wherein the outer sleeve contacts the end cap preventing fluid flow from the pour spout.
The pour spouts are opened by rotating the outer sleeve to first or second indexing positions. By rotating the outer sleeve either clockwise or counterclockwise relative to the inner sleeve, the outer sleeve is adapted to be slid to either of two open positions permitting fluid to flow at either of two flow rate through the fluid tube and out of the pour spout. Said patents attempt to address concerns going to spillage and flow rates. The present invention further addresses these problems, as well as certain new problems that have come to light in view of regulatory changes.
In this last regard, it is noted that industry regulations changed in January of 2000 that no longer required standardized flow rates. The actual outlet end of the spout could thus be reduced for cooperative engagement within or adjacent a vehicular fuel intake aperture. It was contemplated, however, that certain accommodative stop structure would help guide and hold the narrowed spout outlet structure in cooperative engagement with a fuel inlet aperture.